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Tuesday, 24 June 2014

So I bought myself a Canon 70D. The EOS 350 had served me well for nearly 10 years, so it was certainly time for an upgrade.

The 70D has far too many features to discuss here, but it has a few that I am already finding indispensable. Firstly, it has a revolutionary new focussing system, which enables it to more or less instantly decide which direction (nearer or further) to go when focussing. The 350 was fast, but the 70D is near-instant, which is crucial when photographing insects. A fully-articulated rear screen enables me to take shots above my head or down at ground level. 20 megapixels means I don't have to get so close, so depth of field can be better. It can operate over wi-fi, so uploading images means less wear and tear on memory card transfers from camera to computer and back again. Video mode means I can tag images with a piece of voice annotation.

Here are a few shots:

This is the 10mm. micromoth Celypha lacunana, which is out in very large numbers on my local hedgerow:

The micromoth Celypha lacunana

And this is the strange-looking hoverfly Xylota segnis:

The hoverfly Xylota segnis

The first time I saw it running quickly over leaves, I thought it was a wasp of some kind with those long, grasshopper-like rear legs.

Formica fusca is the ant which is most numerous in my heathy area, and they can often be seen climbing Willow bushes to 'milk' their aphids. This one was behaving very strangely, cropping the fine hairs from a Bramble leaf. I have absolutely no idea why it was doing that.

Formica fusca, an ant

Orchids started flowering last week, so now is the time to see them at their best.

Common Spotted Orchid, with a touch of Heath Spotted

'Cleaner' Common Spotted Orchid

I also took a record shot of the white version of Bush Vetch, which is still slowly expanding its range along a ditch:

White variant of Bush Vetch

It's still early days for the camera, but I think the results are shaping up well for the future.

Friday, 6 June 2014

I was invited to help with a couple of surveys this week and found some interesting specimens. The first location was a disused mill with associated ponds, dams, millraces and reservoirs. This is a wonderful site covering tens of acres, with old deciduous woodland and various meadows in addition to the water features mentioned above. It was also on limestone, which I always find interesting. Sedge and grass specialists would have a field day here. We were actually hoping for butterflies, but it was dull and wet, so I concentrated on leafmines, which are always there despite the weather.

First interesting specimen was this one on Ground Elder:

Blotch mine on Ground Elder

Most mines are specific to family, perhaps even species of plant, but this is the mine of Phytomyza angelicastri, which is more usually found on Angelica. So this isn't a new mine for me, but it is a new host for that species. I can now add that insect to plant association in my Donegal Wildlife database.

There were a couple of specimens of Early Marsh Orchid in the middle of a path next to one of the ponds:

Early Marsh Orchid

Sawflies are one of the least-studied groups of insects. They are difficult to identify to species, often requiring dissection for a certain identification. The larvae are also poorly documented, and since they can change their appearance dramatically when they shed their skin, identifications are very tricky. One or two species can be identified from photographs, but first you have to eliminate similar-looking Ichneumonids. This is the sawfly Tenthredo livida (male):

The sawfly Tenthredo livida (male)

One of the main characters that can be used to separate Ichneumonids and Sawflies is the microsculpture on the thorax. In this case, it looks like the letter 'M':

Close-up showing microsculpture on the thorax

Ichneumonids tend to have a smoother thorax, although that's not a hard and fast rule.

This Eristalis hoverfly caused me a few id problems.

Eristalis nemorum (male)

One of the main keying features for these is the facial stripe, which is more or less absent on this specimen. So that immediately keys to Eristalis arbustorum. But this didn't look right for that species. The key caters for specimens of E. arbustorum with a slight facial stripe caused by wear and tear, but this still didn't key out properly until I took into account the very narrow stigma (dark thin line) on the outside edge of the wing. This is a feature of Eristalis nemorum, which I am now told can sometimes be found with no facial stripe. I suspect that some of this variation is caused by the fact that my local specimens are found on acid soil, but this specimen was on lime.

Caddis flies are always found near water, since the larvae live at the bottom of ponds, ditches, etc.

Caddis Fly

Shield Bugs, in common with all other Heteroptera, go through a series of nymph stages before becoming adult. In each stage they become slightly more like the adult in size and pattern. This appears to be a final-instar (full-size, with larger wing-cases) nymph of Pentatoma rufipes:

Final instar nymph of the shieldbug Pentatoma rufipes

There was a family of Mute Swans on one of the mill ponds:

Mute Swan and cygnets

I wouldn't normally go near swans with cygnets, but I was advised that this pair were calm enough. The male quickly got between me and the family and hissed a bit, but stayed to the side, watching me until he saw that I was just taking photographs. Interestingly enough, this is new to my species list.